/Engine/Source/Runtime/CoreUObject/Public/UObject/PackageTrailer.h
True if the builder was created and appended successfully and false if any error was encountered
bool BuildAndAppendTrailer ( [FLinkerSave](API\Runtime\CoreUObject\UObject\FLinkerSave) * Linker, [FArchive](API\Runtime\Core\Serialization\FArchive) & DataArchive, int64 & InOutPackageFileOffset )